लुकबैक समय कैलकुलेटर — सूत्र
## Lookback Time
Light travels at a finite speed, so observing a distant object means seeing it as it was in the past.
### Simple Estimate
**t ≈ d / c**
where d is in light-years and t in years. Since 1 Mpc ≈ 3.262 Mly, the lookback time in millions of years equals the distance in Mpc × 3.262.
For very large distances, cosmological expansion makes this an underestimate of the true lookback time.
Light travels at a finite speed, so observing a distant object means seeing it as it was in the past.
### Simple Estimate
**t ≈ d / c**
where d is in light-years and t in years. Since 1 Mpc ≈ 3.262 Mly, the lookback time in millions of years equals the distance in Mpc × 3.262.
For very large distances, cosmological expansion makes this an underestimate of the true lookback time.
हल किया गया उदाहरण
A galaxy is 100 Mpc away.
- t ≈ 100 Mpc × 3.262 Mly/Mpc = 326.2 Mly
- We see this galaxy as it was 326 million years ago.
- In Gyr: 0.326 Gyr